Building a Stereo Audio Amplifier Using NPN Transistors

Projects
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I’m about to embark on a DIY project where the goal is to build a stereo audio amplifier using NPN transistors for portable audio. The amplifier will be able to take an audio signal, amplify it, and drive a pair of speakers with clean, distortion-free audio.

When designing the amplifier circuit, I have two choices for the NPN transistor, one is the 2SC1775A, and the other is the 2N2222. Does anyone know which one will perform better?

2N2222 Specs

2SC1775A Specs

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Hi Jason
I don’t think either of those will do much driving of a speaker.

There is a bit more to this than throwing a couple of transistors and a few bits on a board.
Cheers Bob

1 Like
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The first place to start is a circuit diagram. These can be very simple of very complex.
There are a number of circuits on this page.

Some of the YouTube videos I checked are not very good or helpful.

Limiting yourself to just those two components is going to be a problem. Especially when you want it “distortion-free audio” and to drive speakers. In the realm of transistors there are many equivalents and some with very minor differences.

All the best
Jim

4

Hi Jason.
Google “transistor audio amplifiers”.
There are literally pages of suggestions. The fidelity of some would be questionable, particularly the ones that appear to have some DC current through the speaker coil.

There are simple and more complicated. I don’t think that simplicity and

really go together.

Depends on just what distortion number you are after. Keeping in mind that in this day and age most heavy guitar type music is distorted on purpose. All in the pursuit of that “sound”
Cheers Bob